This paper presents a centrifuge study of the dynamic response of a single bucket foundation and a 4-bucket foundation in a silty sand under cyclic lateral loads. The ice-sheet induced structural vibration was simulated as an equivalent cyclic lateral load applied by an electro-magnetic actuator. The effects of load intensity and foundation rigidity on the behavior of the foundation were examined. The results indicated that excess pore pressures near a single bucket reached the highest value within a depth of 1.0-1.5 m. Liquefaction of soil at shallow depths was likely to occur in the first 1-3 hours. Significant displacements were induced during long-term excitation. The foundation rigidity has a strong effect on the dynamic response of the bucket. In a 4-bucket model, the excess pore pressure and its depth of influence were conspicuously reduced as compared with that of a single bucket. © 2010 Taylor & Francis Group, London.